#include <stdio.h>
#include <stdbool.h>

char* reverseString(char* s) {
    char *pStart;
	char *pLast;
	bool bRight, bLeft;
	char tmpChar;
	
	pStart = s;
	pLast = s;
	for(;*(pLast+1) != '\0' && *pStart != '\0'; pLast++);
	
	
	while(pStart != pLast)
	{
		if(*pLast != *pStart)
		{
			tmpChar = *pLast;
			*pLast = *pStart;
			*pStart = tmpChar;
		}
		pStart++;
		if(pLast != pStart)
			pLast--;
	}
	pStart = s;
	
	return pStart;
}

int main(void)
{
	char str[] = "";
	
	printf("%s\n", reverseString(str));
	return 0;
}